This invention relates to a gripping apparatus for use as an industrial manipulator for gripping items, more particularly to an improvement of the gripping apparatus used in a machine which may be removed from one or more shafts mounted in the machine or without sliding the gripper apparatus off an end of the shafts or removing the shafts from the machine.
Presently, there exist a number of machines that perform the function of inserting envelopes, manipulating garbage bags for packaging, and generally for transferring items on a machine from one location on the machine to other locations on the machine.
Many of the envelope inserting machines have the capacity for performing the functions of separating inserts from a stack, opening the envelopes, inserting mailing inserts inside the envelopes, putting predetermined printed matter on the envelopes, and sealing the envelopes. Having a machine that can perform all these functions can be very beneficial to the user, especially for the user having a large capacity of mailings to be mailed. However, one major disadvantage of using this type of machine is the time and expense used to repair and service the machines. Parts of the machines which require substantial time and cost to repair and service include gripper arms used to grip and move mailing inserts on the machine.
Normally, when an attached gripper arm on the machine needs to be removed for repair or replacement, the entire shaft or shafts to which the gripper arm is attached must be removed from the machine. The existing one piece design for a gripper arm body requires that both a swing shaft and an operating lever shaft be removed. Prior to removing the shafts, extensive time is required to prepare the shafts for removal. The gripper arm is fastened to the swing shaft by tapered pins and set screws. The tapered pins can only be removed from the back of the gripper arm. To move out the pins, the drive must first be disconnected, and then the arms have to be pivoted upside down placing the small end of the tapered pins in position for the removal. The pins are individually removed with a punch device. Additionally, there is a bell crank mounted on the shaft that has two pins that must be removed, and the gripper arm also has a pin that must be removed. The pusher arm must be unclamped and removed. Set screws in collars mounted on the shafts, the gripper arm drive and gripper arms must be loosened. The operating shaft must be removed also. In order to remove the operating shaft, the positioning collar must be removed. The operating lever must be loosened and the operating rod unclipped. After completing these steps the operating shaft can be pulled out of the arms and machine. With the operating shaft removed, each gripper arm (up to six per machine) can be moved to the left or the right to deburr their set screw marks on the shaft. With all the set screw burrs removed, the shaft can be removed slowly to avoid gripper arm damage. Additionally, since all the gripper arms in an inserter machine are mounted on the same set of shafts, other gripper arms attached to the shafts must be removed in order to remove the one gripper arm in need of repair or replacement. Each gripper arm is usually attached to a shaft by one tapered pin, therefore, each tapered pin must be removed. Additionally, collar members attached to these shafts by set screws must be removed. In essence, a number of taper pins must be removed to remove each gripper arm from the shaft and each collar member from the shaft, all in order to just remove one gripper arm. Conversely, when placing a repaired or replacement gripper arm back on the shaft, the other gripper arms must be placed back on the shaft, and repositioned along with the replacement gripper arm on the shaft. Since, removal of a standard gripper arm requires readjustment of all the removed parts, the replacement process could well exceed 2 hours.
The present invention contemplates eliminating the aforementioned disadvantages of the gripping devices which are mounted on shafts.
It is, therefore, an object of the present invention to provide an improved gripper arm which provides for minimal need of time consuming and costly repair and replacement of gripper arms on a machine utilizing gripper arms mounted on shafts.
In order to accomplish the above described objects, there is provided in the present invention an improved gripping arm assembly having an two-piece gripper arm body comprised of a arm main body and an arm clamp, attachment means for attaching the two-piece gripper arm together and onto one or more shafts, a gripper jaw, a two-piece operating lever, and an operating rod. The two-piece gripper arm body and operating lever construction eliminates the need to remove a shaft from the machine or other gripper arms from the shaft when replacing a gripper arm or operating lever. Only a small number of screws need to be removed to separate the gripper arm into two detached pieces, therefore, greatly simplifying the removal of the complete gripper arm from the inserter machine. The whole process only takes a few minutes to complete. To replace a gripper arm mounted on a shaft requires clamping the two pieces of the gripper arm together around the shafts and securing the screws and re-clipping an operating rod. This replacement process only takes a few minutes as well.